v0.16.0
Ignore ImportError with `subprocess.check_output` for GAE compatibility (issue #231)
Apply Christopher Arndt's ``newsuper`` fix for PyQt subclasses (issue #160)
Add more underscore-prefixed imports to `tkinter` (issue #233)
Use the presence of `builtins` rather than `configparser` to indicate the future/src folder
Comment out PEP 461 tests for now
Merge branch 'master' into v0.15.x
Add fix for issues #235 and (probably) #213
Bump version to v0.16.0